Definition: In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.
Input: ['6463', '871', '5781', '283', '9653', 'f', '9661', '3365', '2889', '5499']

f